Production of dyeings and prints on textile material



Patented n... 10, 1940 PRODUCTION OF DYEINGS AND PRINTS ON TEXTILEMATERIAL Ben Verity, Fall River, Mass, assignor, to the firm Durand &Huguenin A. G., Basel, Switzerland No Drawing. Application May 18, 1939,Serial No. 274,431. In Germany May 23., 1938 Claims.

is of duller greener tintas compared with the bright blue tint of theN-dihydro-1:2-2':1'-dianthraquinoneazine and is therefore tinctoriallyvalueless.

This disadvantage is particularly noticeable when the so-called steamingprocesses are used for the development in which-the ester salt togetherwith a suitable oxidizing agent, for instance sodium chlorate and anagent which yields sulphocyanide or diethyltartrate is printed on thematerial and the colour after-developed by steaming (see Germanspecification No. 433,146 and U. S. Patent 1,747,107).

oxidizable so-called bufier substances is recommended; these allow thenormal development of the dyeing but are more easily oxidizable than isthe vat dyestufi developed so that any excess of oxidizing agent istaken up and the dyeing protected from over-oxidation. This processyields in very many cases good anduseful results. In the case oftetrasulphuric acid esters of the tetrahydro-1:2-21'-dianthraquinoneazine group, the process of U. S. Patent 1,779,305 isnot unconditionally permissible. In spite of the useof large proportionsof such buffer substances over-oxidation may occur.

In this connection attention must be called also to the process ofGerman specification No. 591,410. In that specification the tint isdeveloped from the tetrasulphuric acid ester without regard toover-oxidation and then the overoxidized tint is reduced to the normalshade by treatment with a reducing agent. This process howevernecessitates a further operation.

The present invention relates to a process in which a normal reliabledevelopment of the aforesaid tetrasulphuric acid ester salts is obtainedby a short steaming owing to the presence in the printing paste ofammonium nitrate in addition to sodium chlorate. Ammonium nitrate actsin this case no doubt as an acid splitting agent, as an oxidizing agentand as a bufier substance. The certainty of the process whichconstitutes the acid under action of heat, for instance ammonium In theU. s. Patent No. 1,179,305 the use of a U posed oftechnical advance ascompared with the known art is exhibited when the material has to be setaside for some time after the printing and before the steaming. Welldeveloped normal tints are obtained by the process or the invention,while for example in using ammonium sulphocyanide instead of ammoniumnitrate greenish dull tints are obtained.

It is to be mentioned that oxidizing catalysts, as for instance,vanadate of ammonia, which are 10 necessary in I the steam developingprocesses hitherto known (see U. S. Patent No. 1,779,305) are generallynot needed in the present process.

The present invention is illustrated by the following examples. 1

Examples I and II For printing the following pastes can be used:

20 Examples of printing paste I II Sodium salt of the tetrasulphuricacid ester of tetrahydro-lz2-2 :1 -dianthraquinoneazine (20 per PartsParts cent strength) 100 100 na 5 Sodium salt ofdimethylaniline-parasulphonic acid. 30 Wnfr 200 Starch tragacanththickening, neutral. 570 500 Ammonium nitrate solution (1:2) 90 90Sodium chlorate solution (1:3) 60 60 Ammonia solution (25 per centstrength) 10 20 Example III 40 Cotton is padded with a padding liquor,com- I Parts Sodium salt of the tetrasulphuric acid ester oftetrahydro-1z2-2' l'z-dianthraquinoneazine (20 per cent strength) 10Water 735 Tragacanth thickening 50 Sodium chlorate solution (of 33 percent strength) Ammonium nitrate solution (of 50 per cent strength)Ammonia (25 per cent strength) 5 The material is dried, steamed for 8minutes, washed, soaped at the boil, rinsed and dried.

In a similar manner derivatives of the tetrasulphuric acid ester oftetrahydro-1:2-2':1-dianthraquinone-azine, as for example tetrahydro-3:3'- dichloro 1:2 2:1 dianthraquinoneazine, may be developed.

It is evident that the present process may be applied for thedevelopment of leuco ester salts of any other vat dyestufl which issensitive or not sensitive to over-oxidation.

What I claim is:

1. In the production of dyeings and prints from dyestufls of theN-dihydro-l:2-2':1-dianthraquinone-azine group with the aid of leucoester salts of these dyestuffs by acid oxidation, a process forobviating overoxidation, which comprises applying to the fibre acomposition containing a tetrasulphuric acid ester of said group and asuitable oxidizing agent, and conducting the development of the dyeingby steam in presence of ammonium' nitrate, which furnishes the necessaryacid in the heat and acts at the same time as buiier substance.

2. In the production of dyeings and prints from dyestuffs of theN-dihydro-l:2-2':1'-dianthraquinoneazine group with the aid of leucoester salts of these dyestuffs by acid oxidation, process for obviatingoveroxidation, which comprises printing onto the fibre a compositioncontaining a tetrasulphuric acid ester oi. said group and a suitable.oxidizing agent, and conducting the development of the dyeing by steamin presence of ammonium nitrate, which furnishes the necessary acid inthe heat and acts at the same time as buffer substance.

3. In the production of dyeings and prints from dyestuffs of theN-dihydro-1:2-2':1-dianthraquirioneazine group with the aid of leucoester salts of these dyestuffs by acid oxidation, a process forobviating overoxidation, which comprises applying to cotton acomposition containing a tetrasulphuric acid ester of this group and asuitable oxidizing agent, and conducting the development of the dyeingby steam in presence of ammonium nitrate, which furnishes the nec essaryacid in the heat and acts at the same time as bufler substance.

4. ,In the production of dyeings and prints from dyestufls of theN-dihydro-1:2-2':1-dianthraquinoneazine group with the aid of leucoester salts of these dyestuffs by acid oxidation, a process forobviating overoxidation, which comprises applying to the fibre acomposition containing a tetrasulphuric acid ester of this group andsodium chlorate, and conducting the development of the dyeing by steamin presence of ammonium nitrate, which furnishes the necessary acid inthe heat and acts at the same time as bufier substance.

5. In the production oi. dyeings and prints from dyestuffs of theN-dihydro-l:2-2:1'-dianthraquinoneazine group with the aid of leucoester salts of these dyestuffs by acid oxidation, a process forobviating overoxidation, which comprises applying to the fibre acomposition containing the sodium salt of tetrahydro-1:2-2:1-dianthraquinoneazine and a suitable oxidizing agent, and conducting thedevelopment of the dyeing by steam in presence of ammonium nitrate,which furnishes the necessary acid in the heat and acts at the same timeas bufi'er substance.

BEN VERI'I'Y.

